Ever since the discovery of sugarcane in New Guinea in 6,000 B.C., our fixation with sugar has been both a complex source of woe (we’ve been known to cry in the face of a perfect chocolate mousse) and worship. (We bow to the altar of fudge.)

So why is it that even long after we’ve eaten past the point of satiation, the taste of sweet—be it from candy, cookies, or cake—holds sway? “There’s a biological imperative of why we crave sugar and fat,” explains Diana Sugiuchi, a registered dietitian and licensed nutritionist with the Baltimore-based Nourish Family Nutrition. “They give us quick energy, which, when we were evolving as a species, was a very good thing. Our brains are biologically programmed to seek out sweets. Eating sweets activates the same receptors in your brain that morphine and heroin do, but it’s easier to get your hands on chocolate.”

Although we may be inclined to seek out sweets, not everyone develops a sweet tooth. “We can taste sweetness at an early age and detect sweetness, but that's not craving” says Benjamin Caballero of The Johns Hopkins Global Center on Childhood Obesity. "Many studies show that whether you like sweets depends on whether your parents consumed them.”

If you do indulge, moderation, not deprivation, is the key, says Sugiuchi. “Some people think you shouldn’t have any sugar at all, but I’m not the food police,” she says. “I tell my clients to build a savings account of treats into their week and budget for the times they are going to have sweets to help them have a normal relationship with sugar. Treats shouldn’t be nutritious—they should just be something you totally love.” Pass the cake, please.